Protecting the MoSi<sub>2</sub> healing particles for thermal barrier coatings using a sol-gel produced Al<sub>2</sub>O<sub>3</sub> coating

Journal article (2018)

Authors

A.L. Carabat (OLD) MSE-1
M.J. Meijerink Student
J.C. Brouwer (OLD) MSE-1
E.M. Kelder RST/Fundamental Aspects of Materials and Energy - AS
J.R. van Ommen ChemE/Product and Process Engineering - AS
S. van der Zwaag Novel Aerospace Materials - Aerospace Engineering
W.G. Sloof (OLD) MSE-1
Research Group
(OLD) MSE-1
Copyright: © 2018 A.L. Carabat, M.J. Meijerink, J.C. Brouwer, E.M. Kelder, J.R. van Ommen, S. van der Zwaag, W.G. Sloof
DOI
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https://doi.org/10.1016/j.jeurceramsoc.2018.02.002
Alumina shell MoSi Self-healing thermal barrier coatings Sol-gel
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Published Date

2018

Language

English

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Research Group

(OLD) MSE-1

Abstract

A successful sol-gel process to encapsulate molybdenum di-silicide MoSi2 particles with a closed and thermally stable Al2O3 layer using aluminium tri-sec-butoxide as a precursor is presented. The processing conditions such as precursor selection and temperature were optimized through analysing the interaction of the MoSi2 particles with the sol. The application of the sol-gel based coating was followed by calcining the coated particles at temperatures between 900 and 1200 °C in Ar. The shell composition and the mechanical stability of the microcapsule were analysed by means of X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. Upon calcining at 1200 °C in Ar, the MoSi2 core remains intact as it is, covered by an α - alumina shell with a thickness of about 0.6 μm. The stability tests proved that the encapsulate particles are about five times more oxidation resistant than the uncoated MoSi2 particles.